Turn the gears slowly and watch each interlocking segment move the next, or see how fast your child can make the caterpillar "crawl" on the wooden base. Their bulky, notched shape makes the colorful gears easy for children to fit onto the color-coordinated pegs, then rotate, remove and rearrange. Includes eight plastic gears. Wood. 4 1/4" x 6" © 2016 Melissa & Doug, LLC. All Rights Reserved.